A weird problem???

[BWatson]

My 300D Starts and runs perfectly until it warms up and then it idles a little rough. If I shut it off and go into a store, It's hard to start when I come out. I did have a recent valve adjustment and I've heard that valves being too tight can cause this, but it didn't start this behavior until 500 or so miles after the adjustment. I plan to replace the fuel filters and see what happens. Other than that, the car has plenty of power warm or cold....I'm clueless. I brought it to my mechanic and it imediately stopped behaving badly so he couldn't tell either.

i breeze through around 190 kph (i'm in the philippines) with my 87 300D and the power of my 6 banger loosened up the major screw holding the alternator pulley in place! can anyone help me with this? i think there is a problem regarding the sequence of the pulley assembly of the alternator? can anyone show me the correct sequence?

[BWatson]

It looks like I'm the pioneer on this one. I noticed the other day that it took a couple of extra seconds to shut down and then, when I came out of the store...hard to start. So, I went on to my next stop and this time I opened the hood and used the stop lever to shut off the motor just to see what would happen. BINGO! Car started perfectly. Going to replace the vacuum shut-off valve tomorrow! I amaze myself sometimes!
As far as the rough idling, I probably will still replace the fuel filters as well.

yeah, that's true. i did the same thing with my 87 300D. but i didnt replace the whole valve system... coz its only the rubber stopper thats causing the problem.. got myself a new stopper.

[adamb]

My 1985 300d was doing the same thing, although it wasn't hard to start, but it wound up being my motor mounts even though they were less than 1 year old. I wasted soooo much effort and money testing/ replacing other things.... Now it works as it should with the new mounts which only cost 13 each.
Have Fun,
Adam

[P.E.Haiges]

B Watson,

If the car has plenty of power, there is nothing wrong with your fuel filters and you will just be wasting your time and money replacing them.

Think of it: When the engine is putting out a lot of power, the fuel is gushing thru the filters. If there was any restriction, you would loose power, especially on a hill. When starting the engine, very little fuel is going thru the filters.

Try some of the other suggestions above if you want to fix your problem.

P E H

[BWatson]

Well...It turns out my vacuum pump was toast and fortunately I get to it before the oil fouled out the whole vacuum system or ruptured the bearing. I had it done....no time for DIY this month but it's all back to normal.

[JMH]

You might also consider having Helga's rack dampened. I too have a 300D (1984 vintage) with untold miles on it, probably around 210k (odo isn't working). The rack dampener is about $26 and is found on the backside of the IP between the oil filter and the pump.....I posted photos of mine this past Sunday. If you have rough idle, that should cure it. The rack dampener is a 12mm specialized bolt approx. 2 inches long with two sets of threads: the first set is to seat it in the injector pump and the second is for the 14mm jam nut. At the tip/end of the bolt shaft is a small metal finger sticking out that is springloaded. The tip of the finger should be beveled convex. If you take yours out and it is ground down to flat, that could be a contributory cause of your "rough idle"...... My rough idle was drivin' me nuts. Replaced Sunday night and all is well!!

Regards,,
John

[JMH]

oops!